Source Of Irrigation Water Research Articles

Wastewater-derived contaminants of emerging concern: Concentrations in soil solution under simulated irrigation scenarios

In response to declineing natural water sources, treated wastewater has been introduced into the water cycle as a new water source for irrigation. However, this practice exposes the agricultural environment to various contaminants of emerging concern. To better understand their fate in the soil and to effectively predict their bioavailability for plant uptake, there is a need to quantify their concentrations in soil solutions. In this study, we examined the concentrations of treated wastewater-derived ​contaminants of emerging concern in soil solutions under three scenarios: (1) shifting from irrigation with freshwater to treated wastewater (FW→TWW scenario), (2) long-term continuous irrigation with treated wastewater (TWW→TWW scenario), and (3) prolonged irrigation with treated wastewater followed by freshwater (TWW→FW scenario). Contaminants of emerging concern including carbamazepine, 1H-benzotriazole, lamotrigine, venlafaxine, and thiabendazole were ubiquitous in the treated wastewater (mean concentrations of 125, 945, 180, 3630, and 90 ​ng/L, respectively) and irrigated soils. Interestingly, their concentrations in the soil solutions were different (higher or lower) from the corresponding concentrations in the irrigation water. In both the freshwater to wastewater (FW→TWW) and treated wastewater to freshwater (TWW→FW) irrigation scenarios, lower contaminant concentrations were observed in soil solutions compared to the prolong treated wastewater irrigation scenario (TWW→TWW), indicating that a steady state condition was not achieved after a single irrigation season. For example, the concentrations of 1H-benzotriazole in Nir Oz soil solutions were 638, 310, and 1577 ​ng/L for the three irrigation scenarios, respectively. Moreover, the ​contaminants concentrations in soil solutions were slightly lower in the TWW→FW irrigation scenario compared to the TWW→TWW scenario. Our data suggest that rain-fed crops are also exposed to treated wastewater-derived contaminants of emerging concern released from the adsorbed phase into the soil solution. The readily-available contaminants concentration in soil solution depends on the physicochemical properties of the molecule, the water type used for irrigation and the irrigation history, the contaminant concentration in the irrigation water, and soil characteristics.

Assessment of Tank Water Spread Area in Cheyyar Sub Basin Using Sentinel 1A Data

A research study was conducted for estimating the water spread area of tanks in Cheyyar sub basin for the year 2022. Tanks are low-cost irrigation water source and play a key role in recharge of ground water. Mapping and regular monitoring of tanks plays an important role in water resource planning. Sentinel-1A SAR data has high potential in estimating water spread area as it is unaffected by cloud cover, light or weather conditions. After processing the obtained satellite data using SNAP software, the water spread area was obtained by threshold approach. The backscattering (dB) value ranged between -30.641 and 22.898 during the course of study. The total water spread area was noticed maximum and minimum during the month of January and July with 5728.20 ha and 1123.44 ha (21.88% and 4.29 % of total tank area) respectively. The total rainfall received in Cheyyar sub basin was about 1290 mm. The water spread area seems to be proportional to the rainfall of previous and current months.

Analysis of Water Quality of Selected Irrigation Water Sources in Gandevi Taluka of Navsari District of South Gujarat, India

Groundwater quality was evaluated for irrigation purpose by collecting the groundwater samples from 20 different locations during pre-monsoon and post-monsoon seasons. These groundwater samples were analyzed for physico-chemical parameters like pH, EC, TDS, major cations, and anions. Furthermore, irrigation quality indices like salinity hazard, chloride hazard, magnesium hazard, carbonate and bicarbonate hazard and sodium hazard were calculated using the analytical results. The average SAR, Na+ ion, PI, MH and IWQI varied from 6.34 to 2.53, 14.13 to 5.44 me/l, 68.31 to 56.76 me/l, 73.16 to 76.72 %, and 44.24 to 31.25 me/l, during pre-monsoon and post-monsoon seasons respectively. Based on the EC, more than 50% of the samples are falling under high salinity category in both seasons. Overall in Gandevi taluka, based on IWQI, 40 % and 45 % surveyed water samples were found falling in severe restriction category of irrigation during before and after monsoon respectively. The study revealed that most of the water samples are exceeding the critical levels of irrigation water quality and it may require careful management to grow suitable crops in the study area. In addition, the study also points out that usage of such a high TDS groundwater for irrigation may cause soil salinity.

Long-term evolution of groundwater hydrochemistry and its influencing factors based on self-organizing map (SOM)

The primary water source for agricultural irrigation in the People's Victory Canal irrigation area was the Yellow River water in the early stage, and the Yellow River water diversion volume decreased in the later stage. Hence, the groundwater became the primary water source for the irrigation area. It is significant for the rational utilization of groundwater resources to explore groundwater hydrochemistry's evolution characteristics and formation mechanism. Based on the hydrochemical data of groundwater and Yellow River in the irrigation area from 1987 to 2022. The spatiotemporal evolution of chemical components of groundwater and the main influencing factors were revealed using traditional hydrochemistry research methods, self-organizing map, and stable isotopes. The results show that the classification results of groundwater and Yellow River water samples by the self-organizing map show regional and phased characteristics. Regionally, the self-organizing map classifies groundwater into five clusters, and Cluster Ⅰ–III of groundwater are mainly distributed in the head, middle and northeast areas. Cluster Ⅳ and V of groundwater are mainly distributed in the northwest region. In terms of time, from 1987 to 2001, the Yellow River water diversion volume was higher, and the ion concentration of groundwater showed a decreasing trend. The ion concentration was close to the Yellow River water ion concentration except in the northwest area. Accordingly, the classification results of the self-organizing map change from Cluster Ⅰ of groundwater to Cluster Ⅱ of groundwater. After 2001, the amount of water diverted from the Yellow River decreased, and the concentration of each ion in the groundwater at the head of the canal and the central area showed an overall increasing trend from 2001 to 2022. The classification results of the self-organizing map change to Cluster Ⅰ of groundwater. Due to the change in runoff conditions and the influence of domestic sewage, the classification results of the self-organizing map in the funnel area in the middle of the irrigation district changed to Cluster III of groundwater after 2013.

HYDROGEOLOGICAL VARIATIONS IN SAHYADRI GROUP AND SATPURA GROUP OF DECCAN TRAPS: COMPARATIVE STUDY OF REPRESENTATIVE WATERSHEDS FROM THE NANDURBAR DISTRICT OF MAHARASHTRA, INDIA

Water is an elixir of the life and groundwater is the main source of drinking, irrigation, and industrial water uses. Occurrence and movement of the groundwater is mainly depending on the hydrogeological characteristics of the rocks. About 80% of the Maharashtra state is occupied by Deccan basalt exhibiting diversity in the groundwater development. In present study, an attempt has been made to do comparative study of Gomai watershed and Amaravati watershed for analyzing the hydrogeological behavior of basalts of Sahyadri Group and Satpura Group of Deccan Traps.

The environmental assessment of soil chemical properties irrigated with treated wastewater under arid ecosystem of Al-Ahsa, Saudi Arabia

PurposeThe present study focused on examining the effect of treated wastewater (TWW) on soil chemical properties. Also, efforts were made to compare the soil chemical properties under TWW irrigation with that under groundwater (GW).Design/methodology/approachDuring the years 2021 and 2022, surface and subsurface soil samples were randomly collected in triplicate by using an auger fortnightly at two depths (20 and 40 cm) from the selected spot areas to represent the different types of irrigation water sources: TWW and GW. Samples of the GW and the TWW were collected for analysis.FindingsThis study examines the impact of TWW on soil characteristics and the surrounding environment. TWW use enhances soil organic matter, nutrient availability and salt redistribution, while reducing calcium carbonate accumulation in the topsoil. However, it negatively affects soil pH, electrical conductivity and sodium adsorption ratio, although remaining within acceptable limits. Generally, irrigating with TWW improves most soil chemical properties compared to GW.Originality/valueIn general, almost all of the soil’s chemical properties were improved by irrigating with TWW rather than GW. Following that, wastewater is used to irrigate the soil. Additionally, the application of gypsum to control the K/Na and Ca/Na ratios should be considered under long-term TWW and GW usage in this study area in order to control the salt accumulation as well as prevent soil conversion to saline-sodic soil in the future. However, more research is needed to thoroughly investigate the long-term effects of using TWW on soil properties as well as heavy metal accumulation in soil.

Greywater irrigation and soil quality: An assessment framework adjustment and application

The on-site use of greywater is increasingly popular for alleviating water stress in various parts of the world, particularly as a water source for irrigation. However, greywater can contain a range of pathogenic bacteria that may compromise public health as well as substances with the potential to induce environmental consequences, such as soil hydrophobicity, accumulation of salts, and damage to plants. While the health issues are being addressed by greywater legislation, its environmental risks are largely ignored. Therefore, the main objective of the current study was to quantify the impacts of greywater irrigation on soils by developing a soil quality index (SQI) using a 14-month planter experiment. The sum of the absolute value of all indicator scores represents the final score of the integrated SQI, which ranges from 0 to 100. Three threshold values were used: <30 represents deteriorated soil quality, 50–70 indicates intermediate quality, and >70 represents optimal quality. The results based on the planter experiment revealed that, after 14 months, the SQI of all raw greywater-irrigated soils was lower than 70, indicating soil functions and plant health might be compromised. The use of scoring functions was a useful tool for quantifying and comparing the effects of greywater irrigation on different soil quality indicators. Integration of all indicator scores into a single SQI quantifies and summarizes the overall beneficial and detrimental effects of greywater irrigation. However, for better understanding and management decisions, SQI scores should be used and interpreted in conjunction with the scores of the single indicators constituting the index. In our experiment, treated ​greywater ​did ​not compromise ​soil quality even after 14 months of irrigation. As such, based on the fact that irrigation with raw greywater might compromise soil quality, treatinggreywater prior to its use is recommended.

Biochar and zero-valent iron sand filtration simultaneously removes contaminants of emerging concern and Escherichia coli from wastewater effluent

Advanced treated municipal wastewater is an important alternative water source for agricultural irrigation. However, the possible persistence of chemical and microbiological contaminants in these waters raise potential safety concerns with regard to reusing treated wastewater for food crop irrigation. Two low-cost and environmentally-friendly filter media, biochar (BC) and zero-valent iron (ZVI), have attracted great interest in terms of treating reused water. Here, we evaluated the efficacy of BC-, nanosilver-amended biochar- (Ag-BC) and ZVI-sand filters, in reducing contaminants of emerging concern (CECs), Escherichia coli (E. coli) and total bacterial diversity from wastewater effluent. Six experiments were conducted with control quartz sand and sand columns containing BC, Ag-BC, ZVI, BC with ZVI, or Ag-BC with ZVI. After filtration, Ag-BC, ZVI, BC with ZVI and Ag-BC with ZVI demonstrated more than 90% (> 1 log) removal of E. coli from wastewater samples, while BC, Ag-BC, BC with ZVI and Ag-BC with ZVI also demonstrated efficient removal of tested CECs. Lower bacterial diversity was also observed after filtration; however, differences were marginally significant. In addition, significantly (p < 0.05) higher bacterial diversity was observed in wastewater samples collected during warmer versus colder months. Leaching of silver ions occurred from Ag-BC columns; however, this was prevented through the addition of ZVI. In conclusion, our data suggest that the BC with ZVI and Ag-BC with ZVI sand filters, which demonstrated more than 99% removal of both CECs and E. coli without silver ion release, may be effective, low-cost options for decentralized treatment of reused wastewater.Graphical

Assessment of the Suitability of the Main Mil-Garabakh Collector for Irrigation

The article presents the results of assessing the content and quality of water in order to determine the possibilities of reusing the waters of the Main Mil-Garabakh Collector and the drainages feeding it for irrigation of agricultural fields. It has been established that the mineralization of these waters is approximately in the range of 0.4-3.6 g/l and, in terms of chemical composition, it is predominantly chloride-sulfate. The existing classifications of collector-drainage waters by chemical composition, the possibility of using them for irrigation are analyzed using the proposed mathematical formulas and recommendations. Statistical analysis of the study results was carried out using Pearson’s χ2 (chi-square) test and Fisher’s exact method. The results obtained showed that about 800 million m3 of collector and drainage water are reserve and can be used mainly as an additional source of water for irrigation.

Assessing Fungal Plant Pathogen Presence in Irrigation Water from the Rio Grande River in South Texas, USA

Irrigation is important in many crop production systems. However, irrigation water can be a carrier of plant pathogens that can enter the system and spread to fields, resulting in crop damage and yield losses. The Lower Rio Grande Valley of South Texas is an important area for agricultural production which depends on the Rio Grande River as a source of water for irrigation. Thus, the presence of plant pathogens in the Rio Grande River could have important implications for crop productivity in the region. Cultured-based methods and molecular identification methods are used for monitoring plant pathogens in irrigation water. However, these methods are labor-intensive and just detect targeted pathogens. To overcome these limitations, in this study, the ITS2 amplicon metagenomic method was applied for evaluating the fungal diversity, composition, and presence of fungal plant pathogens in irrigation water from the Rio Grande River as it leaves the water reservoir (WR) and it arrives at an irrigation valve at a farm (FA). Results from the Shannon (WR = 4.6 ± 0.043, FA = 3.63 ± 0.13) and Simpson indices (WR = 4.6 ± 0.043, FA = 3.63 ± 0.13) showed that there are significant differences in the fungal diversity and community structure between the two locations and the PCA analysis showed a clear differentiation between both fungal communities. Several OTUs identified in both locations included potential plant pathogens from diverse genera including Cladosporium, Exserohilum, and Nigrospora, while others such as Colletotrichum and Plectosphaerella were found only in one of the two locations assessed. This work indicates that microbes, including plant pathogens, may enter or exit throughout the irrigation-water distribution system, thereby modifying the microbial community composition along the way. Understanding the dynamics of plant pathogen movement in irrigation water systems can help growers identify risk factors to develop measures to mitigate those risks. This study also shows the usefulness of the metagenomic approach for detecting and monitoring plant pathogen in irrigation water.

Comparative Study on Crop Diversification in Tribal and Non-tribal Area of Chhattisgarh, India

This paper aims to measure crop diversification for a uniform data set of 21 year in tribal and non-tribal area which includes eight districts of Chhsttisgarh state of India namely Bastar, Kondagaon, Balrampur and Surguja (In tribal region) and Raipur, Rajnandgaon, Durg and Dhamtari (in Non-tribal region). At the same time it focuses on status and changing pattern of crop diversification in the districts with a comparative outlook of both. Data used for the study were collected from year 2001 to 2022 and whole study was divided in to seven periods and separate analysis was done for all period. Simpson index were used to measure the crop diversification in the districts for comparative study. Results of the study shows complete diversification was found in the tribal area in all period through all index and likewise in Surguja and Balrampur district crop specialization was found more than Durg and Raipur districts of non-tribal area. During the study I was found that higher indices observed in the tribal area than non-tribal area. The results have revealed that in almost all crops group very low diversification indices were observed. The study has suggested that despite plenty of natural resources available in the state, the economic improvement of farmers is in infancy. Pre-requisite infrastructural facilities like cheap sources of irrigation water (assured irrigation as the monsoon in the present decade had been erratic and scanty rainfall) and extension of technological know-how (quality seeds and fertilizers), may acts as catalyst in diversification of agriculture towards high-valued crops. These developmental efforts may be helpful in fetching good incomes by the cultivators.

An Assessment of Irrigation Water Quality with Respect to the Reuse of Treated Wastewater in Al-Ahsa Oasis, Saudi Arabia

Irrigation water quality is important to sustain agricultural productivity. The primary irrigation water sources in Al-Ahsa Oasis, KSA, are groundwater wells, mixed with treated wastewater and agricultural drainage. This study sought to evaluate irrigation water quality in Al-Ahsa Oasis with the aid of using irrigation water quality indices (IWQIs). One hundred and forty-eight different water samples were collected from various irrigation water resources throughout Al-Ahsa Oasis. The investigated physiochemical characteristics include pH, temperature, TDS, EC, turbidity, free chlorine, total hardness, cations (Na, K, Ca, Mg), anions (Cl, CO3, HCO3, SO4), organic matter indices (DO, BOD, COD), and nutrients (NH4, NO3, PO4). The IWQIs used in this study include salinity hazard, sodium adsorption ratio (SAR), Kelly’s ratio (KR), soluble sodium percentage (SSP), Permeability index (PI), residual sodium carbonate (RSC), and magnesium hazard (MH). The results indicated that treated wastewater mixed with groundwater is acceptable for irrigation. Spatial variations in irrigation water quality throughout Al-Ahsa are associated with water resources. For instance, groundwater mixed with agricultural drainage has the highest values of TDS, cations, and anions, whereas the lowest values were reported for treated wastewater, reflecting the good efficiency of wastewater treatment plants. The IWQI results revealed that 4.1% and 62.1% of the investigated irrigation water samples were considered good (class III) and satisfactory (class IV) for irrigation, respectively, whereas 33.8% of the collected water samples fall within the severe irrigation restrictions. Moreover, 79.7% of the investigated water samples were classified to have high to very high salinity hazards (C3, C4) and medium to high sodium hazards (S2, S3). Regular monitoring and assessment of treated water quality and wastewater treatment plant efficiency are important factors in achieving the sustainability of treated wastewater reuse in irrigation and consequently food security.

Value of Surface Rule Coefficient (C) in Uwemanje Village, Kinovaro District, Sigi Regency

Along with the increasing population growth, the demand for water and land needs also increases. So it tends to cause changes in land use, especially forests, which will affect the water system function of a watershed. This shows that there is a need for conservation efforts to maintain the sustainability of the watershed and its water availability. Land use is a reflection of human activities on land. Land use can be detected based on the land cover. Flood disasters occur due to land use that is not suitable for its designation. Changes in land use result in changes in surface water runoff which can be known based on the coefficient of surface runoff. The greater the rain that occurs, the greater the surface flow, resulting in floods and landslides. The Uwemanje sub-watershed is a hydrological regulator as well as a source of irrigation water for the villages of Porame, Binanngga, Baliase, Boya Baliase, Padende, Sibedi and Uwemanje Alone. The Uwemanje sub-watershed has a very important role in life, especially the daily needs of the Uwemanje community as well as agriculture, animal husbandry and plantations. To find out whether the hydrological characteristics of the Uwemanje sub-watershed are getting better or worse, the flow trend of the Uwemanje sub-watershed can be seen by calculating the runoff coefficient (C), by first analyzing the discharge and rainfall. This research was conducted from April to June 2022 in Uwemanje Village, Kinovaro District, Sigi Regency, and Central Sulawesi Province. The method used to determine the value of the runoff coefficient (C) is the rational method. Based on the observations and measurements made in this study, the results showed that the area of the Uwemanje Village watershed was 12,470,000 m², daily discharge was 12,966.57 m³, rainfall was 0.07893 meters, and the runoff coefficient (C) was 0.0013. The hydrology of the water catchment area (DTA) of the Uwemanje Village is still in a stable condition, which means that the forest with its function as a water regulator has not experienced high physical disturbances.

Multiple-point statistical modeling of three-dimensional glacial aquifer heterogeneity for improved groundwater management

Quaternary glacial aquifers are important water sources for irrigation in many agricultural regions, including eastern Nebraska, USA. Quaternary glacial aquifers are heterogeneous, with juxtaposed low-permeability and high-permeability hydrofacies. Managing groundwater in such aquifers requires a realistic groundwater-flow model parameterization, and characterization of the aquifer geometry, spatial distribution of aquifer properties, and local aquifer interconnectedness. Despite its importance in considering uncertainty during decision-making, hydrofacies probabilities generated from multiple-point statistics (MPS) are not widely applied for groundwater model parameterization and groundwater management zone delineation. This study used a combination of soft data, a cognitive training image, and hard data to generate 100 three-dimensional (3D) conditional aquifer heterogeneity realizations. The most probable model (probability of hydrofacies) was then computed at node spacing of 200 × 200 × 3 m and validated using groundwater-level hydrographs. The resulting hydrofacies probability grids revealed variations in aquifer geometry, locally disconnected aquifer systems, recharge pathways, and hydrologic barriers. The profiles from hydrofacies probability at various locations show spatial variability of the streambed and aquifer connectivity. Groundwater-level hydrographs show evidence of these aquifer characteristics, verifying the general structure of the model. Using the MPS-generated 3D hydrofacies probability and hydrologic data, a novel workflow was developed in order to better define high-resolution groundwater management zones and strategies. In general, the conditional probability of hydrofacies helps improve the understanding of glacial aquifer heterogeneity, the characterization of aquifer-to-aquifer and streambed-aquifer connections, and the delineation of groundwater management zones. This MPS workflow can be adapted to other areas for modeling 3D aquifer heterogeneity using multisource data.

Wastewater Irrigation and Accumulation of Heavy Metals in Vegetable Crops (Broccoli and Cauliflower)

The present study was conducted aiming to determine the effects of different irrigation water sources on some heavy metal uptake by winter crops (Cauliflower and Broccoli). This experiment was laid in a Randomized Complete Block Design (RCBD) with three replications, and three water irrigation sources (Clean water, Wastewater, and alternate use of the a clean-water followed by two Wastewater irrigation, under the surface irrigation system, during the growing seasons in 2018-2019. The results showed that Broccoli crops heavy metal uptake (Pb, Cd, Fe and Cu) were significantly higher in broccoli irrigated with clean and waste water sources alternatively (B-W2 Treatment) (0.0250 ± 0.000, 0.0421 ± 0.001, 4.2247 ± 0.001, and 0.1513 ± 0.001),respectively, compared to the rest of other treatments while the lowest concentrations of the studied heavy metals (Pb, Cd, Fe and Cu) recorded in cauliflower irrigated with clean water (C-C1 treatment) (0.0239 ± 0.000, 0.0383 ± 0.001, 4.2077 ± 0.001 and 0.1447 ± 0.001), respectively.

Water and Food Sustainability in the Riparian Countries of Lake Chad in Africa

Lake Chad is a strategic water resource shared by more than 40 million people in Sub-Saharan Africa. In the 1960s, it served as a primary source of water for irrigation and fishing in the region, but the capacity of Lake Chad to supply water for irrigation plummeted by 90% at the beginning of the twenty-first century. With some initiatives taken by the neighboring countries, Lake Chad has recovered about 5% of its water volume in recent years. This research conducted an extensive literature review on Lake Chad and its riparian countries. The four major riparian countries were given particular attention due to their significant stake in the sustainability of lake Chad. This review identified and analyzed the water usage trends in this region, both before and after the lake’s decline in water levels. Our research findings revealed that riparian countries around Lake Chad have experienced an 80% increase in population growth and that the lake has now been reduced to 10% of its original size in the 1960s. Animal production in the region has increased significantly, too, particularly in Chad, and this increase of over 75% has contributed to the conflicts between farmers and herders in the region. The possible solutions proposed for the restoration of Lake Chad include increased water harvesting activities in the basin, developing a legal framework for sustainable water use, incentive-based policies for stakeholders to mitigate climate extremes events, establishing a joint water administration for the basin, and introducing regenerative agricultural practices with a highly efficient micro irrigation system.

Quantifying irrigation uptake in olive trees: a proof-of-concept approach combining isotope tracing and Hydrus-1D

ABSTRACT An isotope-enabled module of Hydrus-1D was applied to a potted olive tree to trace water parcels originating from 26 irrigation events in a glasshouse experiment. The soil hydraulic parameters were optimized via inverse modelling by minimizing the discrepancies between observed and simulated soil water content and soil water isotope (18O) values at three soil depths. The model’s performance was validated with observed sap flow z-scores and xylem water 18O. We quantified the source and transit time of irrigation water by analysing the mass breakthrough curves derived from a virtual tracer injection experiment. On average, 26% of irrigation water was removed by plant transpiration with a mean transit time of 94 hours. Our proof of concept work suggests that transit time may represent a functional indicator for the uptake of irrigation water in agricultural ecosystems.

Effect of Working Pressure on the Anticlogging Performance of Micro-Sprinkling Hose with Different Structures

A micro-sprinkling hose is a new type of water-saving irrigation equipment, which can become clogged when using sand-laden surface water sources for irrigation. To test the clogging process and mechanism of the micro-sprinkling hose, as well as the influence of working pressure and hose structure, an intermittent micro-sprinkling irrigation experiment was performed using four different micro-sprinkling hoses with different folded diameters (45, 45, 48, and 60 mm). The number of orifices in the single-cycle orifice cluster was three, five, five, and five. The results showed that, when the working pressures were 30 and 40 kPa, the micro-sprinkling hose was prone to complete blockage. When the working pressures were 50 and 60 kPa, the micro-sprinkling hose was partially clogged. The structure of the micro-sprinkling hose affected the mass and gradation of the deposited sediment by mediating the flow rate inside the hose. The particle size range and content of sediment under irrigation using the N48-5 (folded diameter = 48 mm, with five orifices) and N60-5 (folded diameter = 60 mm, with five orifices) hoses were much larger than those of the original soil samples. Micro-sprinkling hose N60-5 had the best anticlogging performance in this study. The results of this study can provide technical support for the application of micro-sprinkler irrigation systems with sand-laden water.

Groundwater governance under climate change in India: lessons based on evaluation of World Bank interventions

ABSTRACT Groundwater is the single largest source of water for irrigation and domestic use in India. Climate change further exacerbates the threat of depletion, reducing food security and increasing the vulnerabilities of resource users. Governance is complicated by externalities associated with its attributes as an invisible and fluid resource which create problems of rivalry and exclusion. Based on theory-based case studies for evaluation of selected World Bank projects, we analyse challenges for groundwater governance and identify factors that contribute to depletion. It highlights the need for integrating and balancing demand and supply-side approaches, including water-efficient irrigation and climate-smart practices.

Effect of Irrigation Management and Transplanting Date on the Rice Production and Water Productivity

ABSTRACT Water supply via irrigation and other water sources during the rice-growing season is vital for obtaining reasonable yield. The present study was carried out to investigate the dual-interacted effects of different irrigation intervals and transplanting dates on the yield, yield components, and water productivity of rice (Hashemi cultivar). The study was conducted in a three replicated randomized complete block design (RCBD) with the split-plot arrangement in two growing seasons (spring and summer) of 2016 and 2017 at Rice Research Institute of Iran, Rasht. The main factor was irrigation at four levels (full flooding, 5-, 10-, and 15-day irrigation intervals), and the second factor was three transplanting dates (April 21st, May 11th, and May 31st). The productivity of irrigation water (WPI) and irrigation water + precipitation (WPI+R) was reported in terms of grain yield and biomass. The highest paddy yield was observed in flooding treatment (4271 kg per hectare) and the irrigation intervals of 5, 10, and 15 days with 3844, 3196, and 3264 kg/ha were in the next rank, respectively. According to the biomass yield, 15-day irrigation interval and flooding irrigation had the highest and lowest water irrigation productivity, respectively. In the study of different transplanting dates, the highest paddy yield (3795 and 3820 kg/ha, respectively) was observed on the May 11th, and May 31st transplanting dates, and the highest water productivity based on paddy and biomass yield was obtained in the April 21st transplanting date. Regarding grain and biomass yield of rice, water productivity, and water use, the five-day irrigation treatment resulted in the best crop grain and biomass yield on April 21st transplanting date.